For decades, scientists believed that early humans avoided rainforests, considering them too challenging for survival. Thick vegetation, limited food sources, and dense canopies were seen as barriers to human habitation.

However, new research has shattered this long-standing assumption. Evidence now suggests that Homo sapiens were thriving in African rainforests at least 150,000 years ago—80,000 years earlier than previously believed.

A Major Shift In Human Evolution Research

The traditional view of early human migration suggests that our ancestors primarily lived in grasslands and open savannas, where hunting and gathering were easier. Rainforests, with their humid climate, hidden dangers, and lack of open space, were thought to be unsuitable environments for early human survival.

However, a recent study conducted by the Human Palaeosystems Research Group has turned this belief upside down. The research team discovered evidence of human presence in the rainforests of Côte d’Ivoire dating back to 150,000 years ago.

Rediscovering An Overlooked Site

The origins of this discovery go back to the 1980s, when Professor Yodé Guédé of l’Université Félix Houphouët-Boigny first excavated a site in Côte d’Ivoire as part of an Ivorian-Soviet research mission.

At the time, the researchers uncovered stone tools buried deep underground, indicating that humans had once inhabited the area. However, they lacked the technology to precisely date the artifacts or determine what kind of environment existed back then.

Fast-forward to today, and modern dating techniques have finally revealed the site’s true significance. Professor Eleanor Scerri and her team revisited the excavation site with cutting-edge scientific tools, knowing that “several recent climate models suggested the area could have been a rainforest refuge in the past as well, even during dry periods of forest fragmentation.”

Pushing The Timeline Of Rainforest Habitation Back

Using advanced dating methods, such as Optically Stimulated Luminescence (OSL) and Electron Spin Resonance (ESR), researchers were able to determine that the artifacts found at the site were buried approximately 150,000 years ago.

Previously, the oldest confirmed human presence in African rainforests dated back only 18,000 years, while the earliest known rainforest habitation in the world was in Southeast Asia, about 70,000 years ago.

This new evidence more than doubles the known timeline, proving that humans had adapted to dense tropical environments far earlier than imagined.

Dr. Eslem Ben Arous, lead author of the study published in Nature, emphasized the importance of this discovery:

“This pushes back the oldest known evidence of humans in rainforests by more than double the previously known estimate.” 

Living In The Rainforest: What The Evidence Tells Us?

Researchers examined sediment samples from the site, searching for clues about the ancient environment. They analyzed pollen, phytoliths (tiny plant remains), and leaf wax isotopes to reconstruct the region’s past ecosystem.

The results confirmed that the site was surrounded by a dense rainforest, filled with tall trees, thick vegetation, and a humid climate—far from the open savannas that early humans were thought to favor. The presence of low grass pollen levels indicated that this was not just a thin strip of forest, but a large, thriving rainforest.

According to Professor Guédé, this is likely just the beginning of many more discoveries:
“This exciting discovery is the first of a long list as there are other Ivorian sites waiting to be investigated to study the human presence associated with rainforest.”

The Adaptability Of Early Humans

This discovery adds another layer of complexity to the story of human evolution. Scientists now have undeniable proof that early humans were not limited to one type of environment.

Professor Scerri explains: “Convergent evidence shows beyond doubt that ecological diversity sits at the heart of our species. This reflects a complex history of population subdivision, in which different populations lived in different regions and habitat types.”